From U.S. Pat. No. 4,026,715, boron-free and fluoride-free glass compositions are known which contain 54.5-60% SiO2, 9-14.5% Al2O3, 17-24% CaO, 2-4% TiO2, 1.5-4% MgO and 1-6% RO (R=Zn, Sr, Ba) and not more than 3% Na2O+K2O+Li2O, and are well suited for drawing fibres and have the properties of E glass. The chemical resistance of these fibres is therefore not satisfactory.
A known fibre according to EP-B-0832046, which has a good temperature stability and chemical resistance, contains 59-62% SiO2, 12-15% Al2O3, 20-24% CaO, 1-4% MgO, 0.1-2% Na2O+K2O, 0-0.9% TiO2 and 0-0.5% Fe2O3. The temperature stability, however, is not satisfactory for a number of uses.
WO03/050049 describes an endless glass fibre consisting of 56-62% SiO2; 11-20% Al2O3; 20-24.5% CaO; 1.5-4% TiO2; 0.2-1% MgO; 0.05-2% Na2O; 0-2% K2O; 0.11-0.3% Fe2O3, wherein shrinkage of the fibre at 800° C. is less than 20%. The transparency of this fibre, however, is not satisfactory for certain uses.